Display device and method of driving the same

ABSTRACT

A display device includes a display portion, a display driver, a touch sensing portion, and a touch driver. The display portion includes data lines, scan lines, and pixels connected to the data lines and the scan lines. The display driver provides data signals to the data lines and sequentially provides scan signals to the scan lines. The touch sensing portion includes sensing electrodes. The touch driver senses a touch input based on a change of a capacitance between the sensing electrodes and calculates a movement speed of the touch input. When the movement speed of the touch input is greater than a reference speed, a first period in which the scan signals and the data signals are provided is reduced in a frame period in which a frame image is displayed.

This application is a continuation of U.S. patent application Ser. No.16/746,100, filed on Jan. 17, 2020, which claims priority to KoreanPatent Application No. 10-2019-0043923, filed on Apr. 15, 2019, and allthe benefits accruing therefrom under 35 U.S.C. § 119, the content ofwhich in its entirety is herein incorporated by reference.

BACKGROUND 1. Field

The disclosure relates to a display device and a method of driving thesame.

2. Description of the Related Art

The display device typically includes a display panel and a driver. Thedisplay panel may include scan lines, data lines, and pixels. The drivermay include a scan driver for sequentially providing scan signals to thescan lines and a data driver for providing data signals to the datalines. Each of the pixels may emit light at a luminance corresponding toa data signal provided through the corresponding data line in responseto the scan signal provided through the corresponding scan line.

Such a display device may further include a touch panel and a touchdriver, detect a touch input through the touch panel, and display ascreen corresponding to the touch input.

SUMMARY

When a scroll screen in which a screen moves in a specific direction isdisplayed by a touch input, a screen abnormality (for example, imagedrag) due to a mismatching between a previous frame image displayedthrough a display device and a reproduced current frame image may occur,and display quality may be degraded.

Embodiments of the disclosure are directed to a display device withimproved display quality and a method of driving the display device.

In an embodiment of the disclosure, a display device includes a displayportion including data lines, scan lines, and pixels connected to thedata lines and the scan lines, a display driver which provides datasignals to the data lines and sequentially provides scan signals to thescan lines, a touch sensing portion including sensing electrodes, and atouch driver which senses a touch input based on a change of acapacitance between the sensing electrodes and calculates a movementspeed of the touch input. In such an embodiment, when the movement speedof the touch input is greater than a reference speed, a first period inwhich the scan signals and the data signals are provided is reduced in aframe period in which a frame image is displayed.

According to an embodiment, each of the scan signal may be synchronizedwith a horizontal synchronization signal, a period of the horizontalsynchronization signal may be reduced, when the movement speed of thetouch input is greater than the reference speed, and the horizontalsynchronization signal may define starts of each of data rows includedin frame data corresponding to the frame image.

According to an embodiment, the display device may further include aprocessor which generates the horizontal synchronization signal. In suchan embodiment, the touch driver may provide a sensing signal to theprocessor when the movement speed of the touch input is greater than thereference speed, and the processor may reduce the period of thehorizontal synchronization signal based on the sensing signal.

According to an embodiment, a refresh rate of the frame image may beconstant.

According to an embodiment, the first period may be within a range ofabout 80% to 90% of a reference time when the movement speed of thetouch input is greater than the reference speed, and the reference timemay be a period in which the scan signals and the data signals areprovided when the movement speed of the touch input is less than thereference speed.

According to an embodiment, when the movement speed of the touch inputis greater than the reference speed, a switching speed of the datasignals may be increased in the frame period.

According to an embodiment, the frame period may include a second periodbetween the first period thereof and a first period of an adjacent frameperiod, the adjacent frame period may be a frame period adjacent to theframe period, and the second period may be increased when the movementspeed of the touch input is greater than the reference speed.

According to an embodiment, the frame period may include a second periodbetween the first period thereof and a first period of an adjacent frameperiod, the adjacent frame period may be a frame period adjacent to theframe period, and the second period may be constant or reduced.

According to an embodiment, the display portion may further includelight emission control lines, the display driver may sequentiallyprovide light emission control signals to the light emission controllines, and the pixels may be connected to the light emission controllines and sequentially emit light based on the light emission controlsignals.

According to an embodiment, the data lines may extend in a firstdirection and may be arranged along a second direction intersecting thefirst direction, the scan lines may extend in the second direction andmay be arranged along the first direction, and the display portion maybe foldable based on a folding axis extending in the second direction.

According to an embodiment, the scan signals may be sequentiallyprovided to the scan lines along the first direction, and the pixels maysequentially emit light in response to the scan signals.

According to an embodiment, the touch driver may calculate the movementspeed of the touch input, and the movement speed may be a speed of thetouch input in the second direction.

In an embodiment of the disclosure, a display device includes a displayportion including data lines, scan lines, and pixels connected to thedata lines and the scan lines, where the display portion displays aframe image through the pixels, a display driver which provides datasignals to the data lines and sequentially provides scan signals to thescan lines, a touch sensing portion including sensing electrodes, atouch driver which senses a touch input based on a change of acapacitance between the sensing electrodes and generates a sensingsignal when a movement speed of the touch input is greater than areference speed, and a processor which varies a refresh rate of theframe image based on the sensing signal.

According to an embodiment, a frame period in which the frame image isdisplayed may include a first period in which the scan signals and thedata signals are provided, and a second period between the first periodand a first period of an adjacent frame period, the adjacent frameperiod may be a frame period adjacent to the frame period, and theprocessor may reduce the first period.

According to an embodiment, the processor may reduce the second period.

According to an embodiment, a frame period in which the frame image isdisplayed may include a first period in which the scan signals and thedata signals are provided, and a second period positioned between thefirst period and a first period of an adjacent frame period, theadjacent frame period may be a frame period adjacent to the frameperiod, and the processor may reduce the second period.

According to an embodiment, the scan signals may be sequentiallyprovided along a first direction, the touch driver may generate thesensing signal when the movement speed of the touch input in a seconddirection is greater than the reference speed, and the second directionmay intersect the first direction.

In an embodiment of the disclosure, a method of driving a display deviceincludes sensing a touch input through a touch sensing portion of thedisplay device, determining whether or not a movement speed of the touchinput is greater than a reference speed through the touch sensingportion, increasing a porch period when the movement speed of the touchinput is greater than the reference speed in a processor, and displayingframe images based on the porch period on a display portion of thedisplay device. In such an embodiment, a second frame image among theframe images is started to be displayed at a time point at which theporch period is elapsed from a time point at which display of a firstframe image among the frame images is ended.

According to an embodiment, a refresh rate of the frame images may beconstant.

According to an embodiment, the increasing the porch period may furtherinclude reducing an update time of frame data corresponding to each ofthe frame images.

In an embodiment of the disclosure, a display device includes a displayportion including data lines, scan lines, and pixels connected to thedata lines and the scan lines, where the display portion displays frameimages through the pixels, a display driver which provides data signalsto the data lines and sequentially provides scan signals to the scanlines, a sensor which generates attitude information by sensing anattitude or a rotation of the display portion, and a processor whichvaries a porch period of the frame images based on the attitudeinformation. In such an embodiment, the porch period is a period betweena time point at which display of a first frame image among the frameimages is ended and a time point at which a second frame image adjacentto the first frame image is started to be displayed.

According to an embodiment, the processor may determine a screenorientation based on the attitude information, increase the porch periodwhen the screen orientation is a first screen orientation, and thescreen orientation may be a direction in which an upper portion or alower portion of each of the frame images is positioned with respect tothe display portion.

According to an embodiment, the scan lines may be arranged along a firstdirection, each of the scan lines may extend in a second direction, andthe first screen orientation may be in the second direction.

According to embodiments of the display device and the method of drivingthe display device, a width of the frame period in which one frame imageis displayed is constantly maintained and the porch period is increasedwhen images corresponding to a screen scroll is displayed. Therefore, insuch embodiments, a display period in the frame period may be reduced,the data signal may be more quickly updated or switched during thereduced display period, and one complete frame image may be more quicklydisplayed. In such embodiments, a screen abnormality that is visuallyrecognized by a user while the scroll screen is displayed may bereduced, and display quality may be improved.

In such embodiments, the display device and the method of driving thedisplay device may minimize an increase of power consumption by fixingthe width of the frame period and reducing only the display period.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features of the invention will become more apparentby describing in further detail exemplary embodiments thereof withreference to the accompanying drawings, in which:

FIG. 1 is a diagram illustrating a display device according to anembodiment of the disclosure;

FIGS. 2A to 2D are diagrams illustrating the display device of FIG. 1 invarious states;

FIG. 3 is a plan view illustrating an exemplary embodiment of thedisplay device of FIG. 1 ;

FIG. 4 is a cross-sectional view illustrating an exemplary embodiment ofa display panel included in the display device of FIG. 3 ;

FIG. 5 is a block diagram illustrating an exemplary embodiment of thedisplay device of FIG. 3 ;

FIG. 6 is a circuit diagram illustrating an exemplary embodiment of apixel included in the display device of FIG. 5 ;

FIG. 7 is a diagram illustrating an exemplary embodiment of the displaydevice of FIG. 3 ;

FIG. 8 is a diagram showing an operation of a touch driver included inthe display device of FIG. 7 ;

FIG. 9 is a signal timing diagram illustrating an exemplary embodimentof signals in the display device of FIG. 3 ;

FIG. 10 is a signal timing diagram illustrating an alternative exemplaryembodiment of the signals in the display device of FIG. 3 ;

FIG. 11 is a signal timing diagram illustrating another alternativeexemplary embodiment of the signals measured in the display device ofFIG. 3 ;

FIG. 12 is a diagram illustrating an exemplary embodiment of an imagedisplayed on the display device of FIG. 3 ;

FIG. 13 is a flowchart illustrating a method of driving a display deviceaccording to an embodiment of the disclosure;

FIG. 14 is a flowchart illustrating a method of driving a display deviceaccording to an alternative embodiment of the disclosure; and

FIG. 15 is a flowchart illustrating a method of driving a display deviceaccording to another alternative embodiment of the disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENT

The invention now will be described more fully hereinafter withreference to the accompanying drawings, in which various embodiments areshown. This invention may, however, be embodied in many different forms,and should not be construed as limited to the embodiments set forthherein. Rather, these embodiments are provided so that this disclosurewill be thorough and complete, and will fully convey the scope of theinvention to those skilled in the art. Like reference numerals refer tolike elements throughout.

It will be understood that when an element is referred to as being “on”another element, it can be directly on the other element or interveningelements may be present therebetween. In contrast, when an element isreferred to as being “directly on” another element, there are nointervening elements present.

It will be understood that, although the terms “first,” “second,”“third” etc. may be used herein to describe various elements,components, regions, layers and/or sections, these elements, components,regions, layers and/or sections should not be limited by these terms.These terms are only used to distinguish one element, component, region,layer or section from another element, component, region, layer orsection. Thus, “a first element,” “component,” “region,” “layer” or“section” discussed below could be termed a second element, component,region, layer or section without departing from the teachings herein.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting. As used herein, thesingular forms “a,” “an,” and “the” are intended to include the pluralforms, including “at least one,” unless the content clearly indicatesotherwise. “Or” means “and/or.” “At least one of A and B” means “Aand/or B.” As used herein, the term “and/or” includes any and allcombinations of one or more of the associated listed items. It will befurther understood that the terms “comprises” and/or “comprising,” or“includes” and/or “including” when used in this specification, specifythe presence of stated features, regions, integers, steps, operations,elements, and/or components, but do not preclude the presence oraddition of one or more other features, regions, integers, steps,operations, elements, components, and/or groups thereof.

Furthermore, relative terms, such as “lower” or “bottom” and “upper” or“top,” may be used herein to describe one element's relationship toanother elements as illustrated in the Figures. It will be understoodthat relative terms are intended to encompass different orientations ofthe device in addition to the orientation depicted in the Figures. Forexample, if the device in one of the figures is turned over, elementsdescribed as being on the “lower” side of other elements would then beoriented on “upper” sides of the other elements. The exemplary term“lower,” can therefore, encompasses both an orientation of “lower” and“upper,” depending on the particular orientation of the figure.Similarly, if the device in one of the figures is turned over, elementsdescribed as “below” or “beneath” other elements would then be oriented“above” the other elements. The exemplary terms “below” or “beneath”can, therefore, encompass both an orientation of above and below.

“About” or “approximately” as used herein is inclusive of the statedvalue and means within an acceptable range of deviation for theparticular value as determined by one of ordinary skill in the art,considering the measurement in question and the error associated withmeasurement of the particular quantity (i.e., the limitations of themeasurement system).

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this disclosure belongs. It willbe further understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art and thepresent disclosure, and will not be interpreted in an idealized oroverly formal sense unless expressly so defined herein.

Exemplary embodiments are described herein with reference to crosssection illustrations that are schematic illustrations of idealizedembodiments. As such, variations from the shapes of the illustrations asa result, for example, of manufacturing techniques and/or tolerances,are to be expected. Thus, embodiments described herein should not beconstrued as limited to the particular shapes of regions as illustratedherein but are to include deviations in shapes that result, for example,from manufacturing. For example, a region illustrated or described asflat may, typically, have rough and/or nonlinear features. Moreover,sharp angles that are illustrated may be rounded. Thus, the regionsillustrated in the figures are schematic in nature and their shapes arenot intended to illustrate the precise shape of a region and are notintended to limit the scope of the present claims.

Hereinafter, embodiments of the invention will be described in detailwith reference to the accompanying drawings.

FIG. 1 is a diagram illustrating a display device according to anembodiment of the disclosure.

Referring to FIG. 1 , an embodiment of the display device 100 includes adisplay area DA.

The display area DA may receive a data signal corresponding to an imagedata and display an image corresponding to a data signal. In such anembodiment, the display area DA may sense a touch input (for example, atouch input by a finger of a user, a touch member, etc.).

The display device 100 may have a rectangular shape in a plan view.Herein, the term “in a plan view” may means “when viewed from a planview in a thickness direction thereof.” The display device 100 mayinclude opposing long sides (for example, a first long side LS1 and asecond long side LS2 extending in a second direction DR2) and opposingshort sides (for example, a first short side SS1 and a second short sideSS2 extending in a first direction (DR1). Corners where the long sidesLS1 and LS2 of the display device 100 meet the short sides SS1 and SS2may be right angled but the disclosure is not limited thereto. In analternative embodiment, the corners may be curved or rounded. A planarshape of the display device 100 is not limited to that illustrated inFIG. 1 , but may be variously modified, e.g., to have circular or someother shapes.

The display device 100 may be a flexible display device. In oneembodiment, for example, at least one area of the display device 100 maybe flexible in a way such that the display device 100 may be bendable,foldable, and/or rollable.

In an embodiment, the display device 100 may effectively display animage in the entire display area DA in a non-deformed state, forexample, in a flat spread state. In such an embodiment, the displaydevice 100 may display an image only in an area of a part of the displayarea DA, for example, an area of a part of an area exposed to the user,in a deformed state, for example, in a bended, folded and/or rolledstate.

FIGS. 2A to 2D are diagrams illustrating the display device of FIG. 1 invarious states. FIG. 1 illustrates a display device in an unfoldedstate, FIGS. 2A to 2D illustrate a display device in a folded state.

Referring first to FIGS. 1 and 2A, an embodiment of the display device100 may be in-folded. In one embodiment, for example, the display device100 may be folded in a way such that the display area DA faces an insidewith respect to a first folding axis FA1. The first folding axis FA1 maybe perpendicular to or intersect the opposing sides (for example, thefirst short side SS1 and the second short side SS2) of the displaydevice 100, but not being limited thereto.

In such an embodiment, the display device 100 may be an in-foldabledisplay device. However, embodiments of the display device 100 are notlimited thereto.

Referring to FIGS. 1 and 2B, an embodiment of the display device 100 maybe out-folded. In one embodiment, for example, the display device 100may be out-folded in a way such that the display area DA faces anoutside with respect to the first folding axis FA1. In such anembodiment, the image is displayed through a front surface of thedisplay device 100, and when the display device 100 is folded, rearsurfaces of the display device 100 may be relatively adjacent or incontact with each other. In such an embodiment, the display device 100may be an out-foldable display device.

In an embodiment, the display device 100 may be folded at a plurality ofmutually different areas.

Referring to FIG. 2C, an embodiment of the display device 100 may bein-folded in a way such that the display area DA faces the inside withrespect to the first folding axis FA1 and a second folding axis FA2.

Referring to FIG. 2D, an embodiment of the display device 100 may befolded in a way such that the display area DA faces the inside withrespect to the first folding axis FA1, and may be further folded in away such that the display area DA faces the outside with respect to thesecond folding axis FA2.

In an alternative embodiment, although not shown, the display device 100may be a rollable display device. In one embodiment, for example, thedisplay device 100 may be rolled in a way such that the display area DAfaces the outside or the display area DA faces the inside. In such anembodiment, at least one area of the display device 100 may be rolled,and a rolling direction is not particularly limited.

FIG. 3 is a plan view illustrating an exemplary embodiment of thedisplay device of FIG. 1 .

Referring to FIGS. 1 and 3 , an embodiment of the display device 100 mayinclude a display panel 110 (or a panel), a display driver, a touchdriver 210, a processor 300, and a sensor 400 (or an attitude sensor).In such an embodiment, the display device 100 may further include aflexible printed circuit board FPC and a main circuit board MFPC.

The display panel 110 may be a flexible display panel. In such anembodiment, the display panel 110 may be configured to be bendable,foldable, and/or rollable. In an embodiment, as described above withreference to FIG. 2A, the display panel 110 may be in-folded withrespect to the first folding axis FA1. However, such an embodiment ismerely exemplary, and embodiments of the display panel 110 are notlimited thereto.

The display panel 110 may include the display area DA for displaying theimage and a non-display area NDA outside the display area DA. In anembodiment, the display panel 110 may include pixels disposed in thedisplay area DA. In such an embodiment, the display panel 110 mayinclude sensing electrodes for sensing the touch input. The displaypanel 110 will be described later in greater detail with reference toFIG. 4A.

The display driver may include a first driver 120 and a second driver130.

In an embodiment, the first driver 120 may receive control signal andinput data (or raw image data) from the processor 300, generate the datasignal based on the control signal and the input data, and provide thedata signal to the display panel 110. In such an embodiment, the firstdriver 120 may generate a scan control signal (and a light emissioncontrol signal) based on the control signal, and may provide the scancontrol signal to the second driver 130.

The first driver 120 may be implemented as an integrated circuit, may bemounted on the flexible printed circuit board FPC (or mounted on acircuit film (not shown) and connected to the flexible printed circuitboard FPC), and may be connected to the display panel 110.

The first driver 120 (and the flexible printed circuit board FPC) may bedisposed adjacent to one long side (for example, the second long sideLS2 (refer to FIG. 1 ) of the display panel 110) and may be connected orcoupled to the one long side of the display panel 110.

In an embodiment, the second driver 130 may sequentially generate thescan signals based on the scan control signal and provide the scansignals to the display panel 110. The second driver 130 may include afirst sub-driver 131 and a second sub-driver 132. The first sub-driver131 may be disposed adjacent to one short side of the display panel 110(for example, the first short side SS1 (refer to FIG. 1 ) of the displaypanel 110 and the second sub-driver 132 may be disposed adjacent to theother short side (for example, the second short side SS2 (refer to FIG.1 )).

In an embodiment, when the second driver 130 receives a light emissiondriving control signal, the second driver 130 may generate the lightemission control signal based on the light emission driving controlsignal, and provide the light emission control signal to the displaypanel 110. In an embodiment, the display panel 110 may receive the datasignal in response to the scan signal, and display the imagecorresponding to the data signal in response to the light emissioncontrol signal.

In one embodiment, for example, the first sub-driver 131 may be a scandriver for generating the scan signal, and the second sub-driver 132 maybe an emission driver for generating the light emission control signal.In one alternative embodiment, for example, each of the first sub-driver131 and the second sub-driver 132 may include the scan driver and thelight emission driver.

The second driver 130 (or a second driving circuit) may be disposed inthe non-display area NDA of the display panel 110. However, the firstdriver 120 and the second driver 130 are not limited thereto.

The touch driver 210 may generate a touch driving signal, provide thetouch driving signal to the display panel 110 (or the sensing electrodeincluded in the display panel 110), receive a sensing signalcorresponding to the touch driving signal, and sense the touch inputbased on the sensing signal. In one embodiment, for example, the touchdriver 210 may sense the touch input based on a change of a capacitancebetween the sensing electrodes included in the display panel 110. In anembodiment, the touch driver 210 may provide information on the sensedtouch input (for example, a magnitude, coordinates, and the like of thetouch input) to the processor 300.

In an embodiment, the touch driver 210 may calculate a movement speed ofthe touch input, and determine whether or not the movement speed of thetouch input is greater than a reference speed. In such an embodiment,when the movement speed of the touch input is greater than the referencespeed, the touch driver 210 may provide the sensing signal (or sensinginformation) to the processor 300. Here, the sensing signal indicateswhether or not the movement speed of the touch input is greater than thereference speed, and may indicate a magnitude, a direction, and the likeof the movement speed. Herein, the movement speed of the touch inputmeans a distance between positions of the touch input per a unit time.

The touch driver 210 will be described later in greater detail withreference to FIGS. 7 and 8 .

The touch driver 210 may be implemented as an integrated circuit, may bemounted on the main circuit board MFPC, and may be connected to thedisplay panel 110 through the flexible printed circuit board FPC.

The processor 300 may generate the control signal and the input data,and provide the control signal and the input data to the display driver(or the first driver 120) through the main circuit board MFPC. In anembodiment, the processor 300 may generate the input data based on theinformation on the touch input provided from the touch driver 210.

In an embodiment, the processor 300 may generate the control signalbased on the sensing signal provided from the touch driver 210. In oneembodiment, for example, when the processor 300 receives the sensingsignal indicating that the movement speed of the touch input is greaterthan the reference speed, the processor 300 may determine that the useris fastly scrolling the image (or a screen) displayed on the displayarea DA of the display panel 110, and may adjust a driving setting value(that is, the control signal) of the display driver. In one embodiment,for example, when the movement speed of the touch input is greater thanthe reference speed, the processor 300 may reduce a display period (thatis, a time duration, in a frame period, during which an image isdisplayed through the display panel 110). In the display period, thedata signal and the scan signal (and the light emission control signal)may be provided to the display panel 110. In one alternative embodiment,for example, when the movement speed of the touch input is greater thanthe reference speed, the processor 300 may increase a porch period (thatis, a time duration between two adjacent display periods).

In an embodiment, the display device 100 may sequentially display frameimages, and a frame period (or a frame period allocated to display oneframe image), in which one frame image is displayed, may include adisplay period (or an active period) and the porch period (or a verticalporch period). A start of the frame period (or a start of frame datacorresponding to the frame period) may be defined or determined by avertical synchronization signal (VSYNC in FIG. 9 ), and a start of datarows included in the frame data may be defined or determined by ahorizontal synchronization signal (HSYNC in FIG. 9 ). The display periodof the frame period may be varied by a period (or a frequency) of thehorizontal synchronization signal HSYNC, and the porch period may bevaried by the period of the horizontal synchronization signal (HSYNC)and a period (or a frequency) of the vertical synchronization signal(VSYNC). In one embodiment, for example, when the period of the verticalsynchronization signal (VSYNC) is constant or fixed, the display periodmay be reduced and the porch period may be increased as the period ofthe horizontal synchronization signal (HSYNC) is shortened.

Changes of the display period and/or the porch period in the frameperiod will be described later in greater detail with reference to FIGS.9 to 11 .

In an embodiment, the sensor 400 may be disposed on one side of thedisplay device 100 and sense an attitude (or a physical rotation) of thedisplay device 100 (or the display panel 110) to generate attitudeinformation (or an attitude sensing signal) of the display device 100.In one embodiment, for example, the sensor 400 may be implemented as anattitude sensor such as a gyro sensor, or an acceleration sensor, andmay sense an angle (or angular rates) formed by the short side (forexample, the second short side SS2 (refer to FIG. 1 )) (or the longside) of the display device 100.

In an embodiment, the processor 300 may determine a screen orientation(or an output direction of the screen, and a viewing mode) of thedisplay device 100 based on the attitude information generated in theattitude sensor 400. Here, the screen orientation may be a direction inwhich the image is output or displayed based on the display device 100(or the display panel 110), a direction from an upper portion to a lowerportion of the image (for example, a character), and a direction inwhich the upper portion (or the lower portion) of the image ispositioned. The display device 100 may include at least two screenorientations. In one embodiment, for example, a first screen orientationmay be in the first direction DR1 with respect to the display device 100shown in FIG. 3 , and the screen orientation may be in the seconddirection DR2.

In an embodiment, when the screen orientation of the display device 100is the first screen orientation (or the second direction DR2), thedisplay device 100 may operate in a first viewing mode, and theprocessor 300 may rotate and/or scale the image data corresponding tothe first screen orientation. In one embodiment, for example, the firstviewing mode may be a vertical direction viewing mode (or a portraitviewing mode) (for example, a state in which upper and lower sides ofthe image are short sides).

In an embodiment, when the screen orientation of the display device 100is the second screen orientation (or the first direction DR1), thedisplay device 100 may operate in a second viewing mode, and theprocessor 300 may rotate and/or scale the image data corresponding tothe second screen orientation. In one embodiment, for example, thesecond viewing mode may be a horizontal direction viewing mode (or alandscape mode) (for example, a state in which the upper and lower sidesof the image are long sides).

In an embodiment, the processor 300 may generate the control signalbased on the screen orientation of the display device 100. In oneembodiment, for example, when the screen orientation of the displaydevice 100 is the second direction DR2 (or when the display device 100operates in the first viewing mode (for example, a portrait viewingmode)), the processor 300 may increase the porch period or reduce thedisplay period. In such an embodiment, when the screen orientation ofthe display device 100 is the first direction DR1 (or when the displaydevice 100 operates in the second viewing mode (for example, a landscapeviewing mode)), the processor 300 may reduce the porch period orincrease the display period.

In an embodiment, the processor 300 may generate or vary the controlsignal based on the attitude information of the display device 100.

In an embodiment, as described with reference to FIG. 3 , the firstdriver 120 for generating the data signal may be disposed adjacent to along side of the display panel 110, and the second driver 130 forgenerating the scan signal may be disposed adjacent to a short side ofthe display panel 110. In an embodiment, the touch driver 210 maydetermine whether or not the movement speed of the touch input isgreater than the reference speed. In such an embodiment, when themovement speed of the touch input is greater than the reference speed,the processor 300 may control the control signal to reduce the displayperiod in the frame period or increase the porch period. In such anembodiment, an update speed of the input data (or the data signal) forthe display panel 110 may become faster, and a screen abnormality (forexample, a screen drag that occurs on a screen switched by a scrollinput) may be improved or alleviated.

FIG. 4 is a cross-sectional view illustrating an exemplary embodiment ofthe display panel included in the display device of FIG. 3 .

Referring to FIGS. 3 and 4 , an embodiment of the display panel 110 mayinclude a substrate SUB, a display portion DISP (or a display layer),and a touch sensing portion TSP (or a touch sensing layer).

Referring to FIGS. 3 and 4 , the substrate SUB may be a flexiblesubstrate. The substrate SUB may be formed of or defined by a thin filmincluding a flexible material, or the like. In one embodiment, forexample, the substrate SUB may include at least one of polyethersulfone(“PES”), polyacrylate, polyetherimide (“PEI”), polyethylene naphthalate(“PEN”), polyethylene terephthalate (“PET”), polyphenylene sulfide(“PPS”), polyarylate (“PAR”), polyimide (“PI”), polycarbonate (“PC”),triacetate cellulose (“TAC”), and cellulose acetate propionate (“CAP”).However, the material of the substrate SUB is not limited thereto, andthe substrate SUB may be formed using a material having flexibility in apredetermined range.

The display portion DISP may be provided or disposed on the substrateSUB. The display portion DISP may include pixels PXL. The pixels PXL maybe provided in the display area DA. Each of the pixels PXL may includean organic light emitting diode, but the pixels PXL are not limitedthereto.

The display portion DISP may further include the first sub-driver 131and the second sub-driver 132 (that is, the second driver 130 (refer toFIG. 3 )). The first sub-driver 131 and the second sub-driver 132 may beprovided in the non-display area NDA. In such an embodiment, the firstsub-driver 131 and the second sub-driver 132 may be disposed or formedon the substrate SUB together with the pixels PXL.

In an embodiment, the display portion DISP may include a flexiblethin-film encapsulation layer for sealing the pixels PXL. The flexiblethin-film encapsulation layer may be an encapsulation layer having amulti-layer film structure including at least one organic film and aninorganic film. In one embodiment, for example, the flexible thin-filmencapsulation layer may include first and second inorganic filmsoverlapping each other and at least one organic film interposed betweenthe first and second inorganic films. In one alternative embodiment, forexample, the flexible thin-film encapsulation layer may be anencapsulation layer having a single-layer film structure including acomplex organic and inorganic material.

In an embodiment, as described above, the display portion DISP is aflexible organic light emitting display panel, but a type and/or a shapeof the display portion DISP is not particularly limited.

The touch sensing portion TSP may be disposed on the display portionDISP and may include a sensing electrode IE (or sensing electrodes). Thesensing electrode IE may be provided in the display area DA, but notbeing limited thereto. The sensing electrode IE may be used to sense anexternal input in a mutual capacitance scheme and/or a self-capacitancescheme. The sensing electrode IE may include a transparent conductivematerial such as indium tin oxide (“ITO”), indium zinc oxide (“IZO”),indium gallium zinc oxide (“IGZO”), ZnO, and indium tin zinc oxide(“ITZO”), but the sensing electrode IE is not limited thereto. In oneembodiment, for example, the sensing electrode IE may include an opaquemetallic material.

In an embodiment, as shown in FIG. 4 , the touch sensing portion TSP maybe directly formed or disposed directly on the display portion DISP, butthe touch sensing portion TSP is not limited thereto. In one embodiment,for example, the touch sensing portion TSP may be implemented as aseparate panel (for example, a touch panel) and the separate panel ofthe touch sensing portion TSP may be coupled to the display portion DISPthrough a separate adhesive layer (for example, OCA, OCR, etc.).

FIG. 5 is a block diagram illustrating an exemplary embodiment of thedisplay device of FIG. 3 . FIG. 5 schematically illustrates elements ofthe display device 100 related to a display function (that is, aconfiguration for displaying the image) of the display device.

Referring to FIGS. 3 and 5 , the display device 100 may include thedisplay portion DISP, a data driver 121, a timing controller 122, andthe second driver 130 (or a scan driver and a gate driver).

The display portion DISP may include the display area DA, and thedisplay area DA may be divided into a plurality of display areas AA1 andAA2 with reference to the first folding axis FA1 (that is, a foldingaxis extending in the second direction DR2). However, this is merelyexemplary, and the number of areas (for example, first and seconddisplay areas AA1 and AA2) defining the display area DA is not limitedthereto.

The display portion DISP may include data lines DL1 to DLm (here, m is apositive integer), scan lines SL1 to SLn (here, n is a positiveinteger), and the pixels PXL. The pixels PXL may be disposed in areasdivided by the data lines DL1 to DLm and the scan lines SL1 to SLn.

Each of the data lines DL1 to DLm may extend in the first direction DR1and the data lines DL1 to DLm may be arranged along the second directionDR2. The second direction DR2 may intersect or substantiallyperpendicular to the first direction DR1. Each of the scan lines SL1 toSLn may extend in the second direction DR2 and the scan lines SL1 to SLnmay be arranged along the first direction DR1.

According to an embodiment, the data lines DL1 to DLm disposed in thefirst and second display areas AA1 and AA2 may be continuously disposedbetween the first and second display areas AA1 and AA2 withoutdisconnection. In one embodiment, for example, the data lines DL1 to DLmmay be continuously disposed between the first and second display areasAA1 and AA2.

In an embodiment, the display portion DISP may further include lightemission control lines EL1 to ELn. In an embodiment, each of the lightemission control lines EL1 to ELn may extend in the second direction DR2and the light emission control lines EL1 to ELn may be arranged alongthe first direction DR1.

The pixels PXL may be connected to the data lines DL1 to DLm and thescan lines SL1 to SLn (and the light emission control lines EL1 to ELn).In one embodiment, for example, a first pixel PXL1 may be provided inthe first display area AA1, and may be connected to a j-th data line DLj(j is a positive integer), an i-th scan line SLi (i is a positiveinteger), and an i-th light emission control line ELi. A second pixelPXL2 may be provided in the second display area AA2 and may be may beconnected to the j-th data line DLj, a k-th scan line SLk (k is apositive integer), and a k-th light emission control line ELk.

First and second power voltages VDD and VSS may be provided to thedisplay portion DISP. The power voltages VDD and VSS may be voltages foran operation of the pixels PXL, and the first power voltage VDD may havea voltage level higher than a voltage level of the second power voltageVSS. In an embodiment, an initialization power voltage Vint may beprovided to the display portion DISP. The first and second powervoltages VDD and VSS and the initialization power voltage Vint may beprovided from a separate power supply or source to the display portionDISP.

The second driver 130 (or the scan driver) may receive a scan controlsignal SCS from the timing controller 122 and generate the scan signalin response to the scan control signal SCS. According to an embodiment,the scan control signal SCS may include a start pulse and a clock signal(or a shift clock). The second driver 130 may sequentially generate thescan signals by sequentially shifting the start pulse using the clocksignal, and may sequentially provide the scan signals to the scan linesSL1 to SLn.

In an embodiment, a period of the clock signal may be variable. In oneembodiment, for example, when a sensing signal DS is provided from thetouch driver 210 to the processor 300 (that is, when it is determinedthat the movement speed of the touch input is greater than the referencespeed through the touch driver 210), the timing controller 122 mayreduce the period of the clock signal or increase the frequency. In anembodiment, a pulse width of the clock signal may be constantlymaintained or fixed, but is not limited thereto. In such an embodiment,when the timing controller 122 reduces the period of the clock signal orincreases the frequency, a total time (for example, a total time inwhich the scan signal is provided in one frame period), in which thescan signal is provided to the display portion DISP, may be reduced, andone complete frame image may be displayed more quickly.

In an embodiment, the second driver 130 may receive the light emissiondriving control signal from the timing controller 122 and may generatethe light emission control signal in response to the light emissiondriving control signal. The light emission drive control signal mayinclude a light emission start pulse and a light emission clock signal(or a light emission shift clock). The second driver 130 maysequentially generate the light emission control signals by sequentiallyshifting the light emission start pulse using the light emission clocksignal, and may sequentially provide the light emission control signalsto the light emission lines EL1 to ELn. A period of the light emissionclock signal may be variable, similar to the period of the clock signal(that is, the clock signal for the scan signal).

The data driver 121 may receive a data control signal DCS and a secondimage data DATA2 from the timing controller 122. The data control signalDCS may include a source start pulse, a source clock signal (or a sourceshift clock), and a source output enable signal (for example, a dataenable signal instructing an output of an effective data signal). Thedata driver 121 may generate data signals corresponding to the secondimage data DATA2 using the data control signal DCS and may provide thedata signals to the data lines DL1 to DLm.

In an embodiment, a period of the source clock signal may be variable.In one embodiment, for example, when it is determined that the movementspeed of the touch input is greater than the reference speed through thetouch driver 210, the timing controller 122 may reduce the period of thesource clock signal or increase the frequency. In such an embodiment,when the timing controller 122 reduces the period of the source clocksignal or increases the frequency, the data signal is provided to thedisplay portion DISP more quickly, and one complete frame image may bedisplayed more quickly.

The timing controller 122 may receive first image data DATA1 (or inputvideo data) and a control signal CS from the processor 300, generate thescan control signal SCS (and the light emission driving control signal)and the data control signal DCS based on the control signal CS, andgenerate the second image data DATA2 by converting the first image dataDATA1. In an embodiment, the control signal CS may include the verticalsynchronization signal (VSYNC), the horizontal synchronization signal(HSYNC), a clock, and the like. In one embodiment, for example, thetiming controller 122 may convert the first image data DATA1 of an RGBformat into the second image data (DATA2 of an RGBG format thatcorresponds to a pixel arrangement in the display portion DISP.

In an embodiment, as shown in FIG. 5 , the data driver 121 and thetiming controller 122 may be separated from each other, but this ismerely exemplary and the disclosure is not limited thereto. In oneembodiment, for example, the data driver 121 and the timing controller122 may be implemented as a single integrated circuit (for example, thefirst driver 120 (refer to FIG. 3 )).

The processor 300 may generate the control signal CS for driving thedisplay driver (that is, the timing controller 122, the data driver 121,the second driver 130 and/or the display portion DISP), and the firstimage data DATA1. According to an embodiment, the processor 300 may bean application processor of a mobile device. However, a type of theprocessor 300 is not limited thereto, and the processor 300 may beanother type of processor matched with a corresponding display device.

In an embodiment, the processor 300 may receive the sensing signal DSfrom the touch driver 210 and may vary the control signal CS based onthe sensing signal DS. In one embodiment, for example, when theprocessor 300 receives the sensing signal DS, the processor 300 maydetermine that the user is fastly scrolling the screen of the displaydevice 100 and vary the control signal CS (for example, the period ofthe horizontal synchronization signal (HSYNC)). In such an embodiment,the timing controller 122 may vary the clock signal, the source clocksignal, and the like based on the varied control signal CS, and thedisplay driver and the display portion DISP may operate based on thevaried clock signal, source clock signal, and the like.

In an embodiment, the processor 300 may receive the attitude informationof the display device 100 (or the display panel 110 (refer to FIG. 3 ))from the sensor 400, and may vary the control signal based on theattitude information. In one embodiment, for example, when the shortside of the display device 100 is parallel to a horizon, the processor300 may determine the screen orientation of the display device 100 asthe first screen orientation, and may reduce the period of thehorizontal synchronization signal (HSYNC) according to the first screenorientation. In such an embodiment, when the long side of the displaydevice 100 is parallel to the horizon, the processor 300 may determinethe screen orientation of the display device 100 as the second screenorientation, and may increase the period of the horizontalsynchronization signal (HSYNC) according to the second screenorientation.

FIG. 6 is a circuit diagram illustrating an example of the pixelincluded in the display device of FIG. 5 . In such an embodiment, thepixels PXL included in the display device of FIG. 5 are substantiallythe same as each other. Accordingly, for convenience of description, thefirst pixel PXL1 will hereinafter be described in detail, and anyrepetitive detailed description of other pixels will be omitted.

Referring to FIGS. 5 and 6 , the first pixel PXL1 may include first toseventh transistors T1 through T7, a storage capacitor Cst, and a lightemitting device LD.

Each of the first to seventh transistors T1 to T7 may be implemented asa P-type transistor, but is not limited thereto. In one embodiment, forexample, at least some of the first to seventh transistors T1 to T7 maybe implemented as N-type transistors.

A first electrode of the first transistor T1 may be connected to asecond node N2 or may be connected to a first power line (that is, apower line to which the first power voltage VDD is applied) through thefifth transistor T5. A second electrode of the first transistor T1 maybe connected to a first node N1 or may be connected to an anode of thelight emitting device LD through the sixth transistor T6. A gateelectrode of the first transistor T1 may be connected to a third nodeN3. The first transistor T1 may control an amount of current flowingfrom the first power line to a second power line (that is, a power linefor transferring the second power voltage VSS) through the lightemitting device LD in correspondence with a voltage of the third nodeN3.

The second transistor T2 (e.g., a switching transistor) may be connectedbetween the data line DLj and the second node N2. A gate electrode ofthe second transistor T2 may be connected to the scan line SLi. Thesecond transistor T2 may be turned on when the scan signal is providedto the scan line SLi to electrically connect the data line DLj and thefirst electrode of the first transistor T1 with each other.

The third transistor T3 may be connected between the first node N1 andthe third node N3. A gate electrode of the third transistor T3 may beconnected to the scan line SLi. The third transistor T3 may be turned onwhen the scan signal is provided to the scan line SLi to electricallyconnect the first node N1 and the third node N3 with each other.Therefore, when the third transistor T3 is turned on, the firsttransistor T1 may be connected in a diode form.

The storage capacitor Cst may be connected between the first power lineand the third node N3. The storage capacitor Cst may store a voltagecorresponding to the data signal and a threshold voltage of the firsttransistor T1.

The fourth transistor T4 may be connected between the third node N3 andan initialization power line (that is, a power line for transferring theinitialization power voltage Vint). A gate electrode of the fourthtransistor T4 may be connected to a previous scan line SLi-1. The fourthtransistor T4 may be turned on when the scan signal is provided to theprevious scan line SLi-1 to provide the initialization power voltageVint to the first node N1. Here, the initialization power voltage Vintmay be set to have a voltage level lower than that of the data signal.

The fifth transistor T5 may be connected between the first power lineand the second node N2. A gate electrode of the fifth transistor T5 maybe connected to the light emission control line ELi. The fifthtransistor T5 may be turned off when the light emission control signalis provided to the light emission control line ELi, and may be turned onin other cases.

The sixth transistor T6 may be connected between the first node N1 andthe light emitting device LD. A gate electrode of the sixth transistorT6 may be connected to the light emission control line ELi. The sixthtransistor T6 may be turned off when the light emission control signalis provided to the light emission control line ELi, and may be turned onotherwise.

The seventh transistor T7 may be connected between the initializationpower line and the anode of the light emitting device LD. A gateelectrode of the seventh transistor T7 may be connected to the scan lineSLi. The seventh transistor T7 may be turned on when the scan signal isprovided to the scan line SLi to provide the initialization powervoltage Vint to the anode of the light emitting device LD.

The anode of the light emitting device LD may be connected to the firsttransistor T1 through the sixth transistor T6 and a cathode may beconnected to the second power line. The light emitting device LD maygenerate light with a luminance corresponding to the current providedfrom the first transistor T1. The first power voltage VDD may be set tohave a voltage level higher than that of the second power voltage VSS sothat the current flows to the light emitting device LD.

FIG. 7 is a diagram illustrating an exemplary embodiment of the displaydevice of FIG. 3 . FIG. 7 schematically illustrates elements of thedisplay device 100 related to a touch sensing function (that is, aconfiguration for sensing the touch input) of the display device.

Referring to FIGS. 3 and 7 , the display device 100 may include thetouch sensor portion TSP and the touch driver 210.

The touch sensing portion TSP may include first sensing electrodes IE1,first signal lines (not shown) connected to the first sensing electrodesIE1, second sensing electrodes IE2, and second signal lines (not shown)connected to the second sensing electrodes IE2.

In an embodiment, the first sensing electrodes IE1 and the secondsensing electrodes IE2 may intersect with each other. The first sensingelectrodes IE1 may be arranged along the second direction DR2 and eachof the first sensing electrodes IE1 may extend in the first directionDR1. The second sensing electrodes IE2 may be arranged along the firstdirection DR1 and each of the second sensing electrodes IE2 may extendin the second direction DR2. The first and second sensing electrodes IE1and IE2 may sense an external input by a mutual capacitance methodand/or a self-capacitance method.

The first and second sensing electrodes IE1 and IE2 may include atransparent conductive material such as ITO and IZO, but not beinglimited thereto. In one embodiment, for example, the first and secondsensing electrodes IE1 and IE2 may include conductive fine wiresincluding an opaque metal, and each of the first and second sensingelectrodes IE1 and IE2 may have a mesh structure (or a mesh pattern).

Each of the first sensing electrodes IE1 may include a first sensorportion SSP1 and a first connection portion CP1. Each of the secondsensing electrodes IE2 may include a second sensor portion SSP2 and asecond connection portion CP2.

Each of the first sensor portion SSP1 and the second sensor portion SSP2may have a rhombic shape, but not being limited thereto. Alternatively,each of the first sensor portion SSP1 and the second sensor portion SSP2may have another polygonal shape. In an embodiment, the first sensingelectrodes IE1 and the second sensing electrodes IE2 may have a shape(for example, a bar shape) without division between the sensor portionand the connection portion.

The first connection portion CP1 connects the first sensor portion SSP1and a first sensor portion SSP1 adjacent thereto and the secondconnection portion CP2 connects the second sensor portion SSP2 and asecond sensor portion SSP2 adjacent thereto.

The touch driver 210 may be connected to each of the first sensingelectrodes IE1 and the second sensing electrodes IE2. The touch driver210 may include an input sensor 211 and a sensing signal generator 212.

The input sensor 211 may generate a touch driving signal, sequentiallyprovide the touch driving signals to the first sensing electrodes IE1,and sequentially receive the sensing signals from the second sensingelectrodes IE2. Capacitances between the first sensing electrodes IE1and the second sensing electrodes IE2 may be changed by the touch input(e.g., a touch thereon by a finger or a pen) and the changed capacitancemay be reflected on the sensing signal and output. The input sensor 211may sense the touch input (for example, the magnitude and coordinates ofthe touch input) based on the sensing signal.

The sensing signal generator 212 may calculate the movement speed of thetouch input based on the touch input sensed by the input sensor 211, anddetermine whether or not the movement speed exceeds the reference speed.When the movement speed exceeds the reference speed, the sensing signalgenerator 212 may generate the sensing signal DS and provide the sensingsignal DS to the processor 300.

Hereinafter, operation of the sensing signal generator 212 will bedescribed in detail with reference to FIG. 8 .

FIG. 8 is a diagram showing an operation of the touch driver included inthe display device of FIG. 7 .

Referring to FIGS. 7 and 8 , the touch driver 210 (or the sensing signalgenerator 212) may calculate a movement speed MV of a touch input basedon continuously sensed touch inputs INPUT_T1 and INPUT_T2.

In one embodiment, for example, the touch driver 210 may calculate themovement speed MV of the a touch input based on a first touch inputINPUT_T1 sensed at a first time point (or a center point of the touchinput sensed at the first time point) and a second touch input INPUT_T2sensed at a second time point.

In an embodiment, the touch driver 210 may calculate the movement speedof the touch input in the first direction DR1, that is, a first movementspeed MV_S1 and the movement speed in the second direction DR2, that is,a second movement speed MV_S2. Here, the first direction DR1 may beparallel to the direction in which the scan lines SL1 to SLn arearranged, and the second direction DR2 may be perpendicular to thedirection in which the scan lines SL1 to SLn are arranged, as describedabove with reference to FIG. 5 .

In an embodiment, the touch driver 210 may determine whether or not thesecond movement speed MV_S2 of the touch input is greater than the firstmovement speed MV_S1. When the first movement speed MV_S1 is greaterthan the second movement speed MV_S2, the touch input may be recognizedas a screen change (or screen scroll) in the first direction DR1.

In an embodiment, the touch driver 210 may determine whether or not thesecond movement speed MV_S2 is greater than reference speeds MVTH1 andMVTH2.

In one embodiment, for example, when the second movement speed MV_S2 isgreater than a first reference speed MVTH1, the touch input may berecognized as a screen change (or screen scroll) in the second directionDR2. In such an embodiment, the touch driver 210 may generate thesensing signal DS and provide the sensing signal DS to the processor300. The processor 300 may increase the porch period in the frame periodand reduce the display period in the frame period while maintaining aduration of the frame period (e.g., maintaining a frame frequency, or arefresh rate of frame images, for example, 60 hertz (Hz)).

In one embodiment, for example, when the second movement speed MV_S2 isgreater than the second reference speed MVTH2, the touch driver 210 maygenerate the sensing signal DS and provide the sensing signal DS to theprocessor 300. The processor 300 may reduce the display period in theframe period while reducing the time duration of the frame period (forexample, increasing the frame frequency or the refresh rate from 60 Hzto 70 Hz).

FIG. 9 is a signal timing diagram illustrating an exemplary embodimentof signals in the display device of FIG. 3 .

In FIG. 9 , the vertical synchronization signal VSYNC, the horizontalsynchronization signal HSYNC, the scan signals SCAN1 to SCANn, and thedata signal DATA in the display device 100 are shown. The first scansignal SCAN1 may be provided to the first scan line SL1, the second scansignal SCAN2 may be provided to the second scan line SL2, the third scansignal SCAN3 may be provided to the third scan line SL3, and the n-thscan signal SCANn may be provided to the n-th scan line SLn.

In a first frame period FRAME1, the display device 100 may operate in afirst mode (or a normal mode). In one embodiment, for example, when themovement speed of the touch input is less than the reference speed, thedisplay device 100 may operate in the first mode.

In the second frame period FRAME2, the display device 100 may operate ina second mode (or a variable mode). In one embodiment, for example, whenthe movement speed of the touch input is greater than the referencespeed, the display device 100 may operate in the second mode for aspecific period.

Each of the frame periods FRAME1 and FRAME2 may include the displayperiod and the porch period. Here, the display period may be defined asa period (time duration) in a frame period when an effective data signalis provided to the display portion DISP (refer to FIG. 3 ) or a periodin a frame period when the scan signals SCAN1 to SCANn and the datasignal DATA are provided to the display portion DISP. The porch period(or a blank period) may be a period in a frame period between an endtime point of a display period and a start time point of a next displayperiod. In one embodiment, for example, the first frame period FRAME1may include a first period P1 as the display period and a second periodP2 as the porch period. In such an embodiment, the second frame periodFRAME2 may include a third period P3 as the display period and a fourthperiod P4 as the porch period.

The vertical synchronization signal VSYNC may include a pulse (forexample, a pulse having a logic low level) and may indicate a start offrame data (that is, data corresponding to a frame period in which oneframe image is displayed).

Ina n embodiment, a period of the vertical synchronization signal VSYNCmay be regularly maintained or fixed. In such an embodiment, a size (ora temporal width) of the second frame period FRAME2 may be equal to asize (or a temporal width) of the first frame period FRAME1. In oneembodiment, for example, each of a refresh rate of a frame image (orframe images corresponding to frame periods including the first frameperiod FRAME1) corresponding to the first frame period FRAME1 and arefresh rate of a frame image corresponding to the second frame periodFRAME2 may be a first frequency FREQ1 (for example, 60 Hz). In such anembodiment, even though the movement speed of the touch input is greaterthan the reference speed, the refresh rate (a frame frequency, or adriving frequency) may be regularly or constantly maintained or fixed.

The horizontal synchronization signal HSYNC may include a pulse (forexample, a pulse having a logic low level) and may indicate a start of adata row (that is, one data row of a plurality of data rows included inthe frame data). The scan signals SCAN1 to SCANn and the data signalDATA (or the data signals DATA1 to DATAn) may be synchronized with thehorizontal synchronization signal HSYNC. The data signals (DATA1 toDATAn) may be sequentially provided through one data line.

In an embodiment, a second period PR2 (or a second horizontal period) ofthe horizontal synchronization signal HSYNC in the second frame periodFRAME2 may be less than a first period PR1 (or a first horizontalperiod) of the horizontal synchronization signal HSYNC in the firstframe period FRAME1. The second period PR2 may be within a range ofabout 80% to about 90% of the first period PR1. The first and secondperiods PR1 and PR2 may be changed according to the refresh rate and thenumber of scan lines. In one embodiment, for example, the first periodPR1 may be about 10.68 microseconds (μs) and the second period PR2 maybe about 9.25 μs.

As shown in FIG. 9 , in the first frame period FRAME1, the scan signalsSCAN1 to SCANn may be sequentially provided to the scan lines based onthe first period PR1. In the second frame period FRAME2, the scansignals SCAN1 to SCANn may be sequentially provided to the scan linesbased on the second period PR2. In such an embodiment, the data signalsDATA1 to DATAn may be provided to the data lines based on the secondperiod PR2. In such an embodiment, a switching speed of the data signalDATA applied to one data line may be relatively increased.

Therefore, a total time during which the scan signals SCAN1 to SCANn andthe data signal DATA are provided in the second frame period FRAME2,that is, a third period P3 (the display period, or the active period)may be less than a total time during which the scan signals SCAN1 toSCANn and the data signal DATA are provided in the first frame periodFRAME1, that is, a first period P1. In one embodiment, for example, thethird period P3 may be within a range of about 80% to 90% of the firstperiod P1 (or the reference time). Therefore, in the second frame periodFRAME2, the data signal DATA1 may be updated more quickly and onecomplete frame image may be displayed more quickly than in the firstframe period FRAME1.

In an embodiment, a second pulse width PW2 of each of the scan signalsSCAN1 to SCANn in the second frame period FRAME2 may be equal to a firstpulse width PW2 of each of the scan signals SCAN1 to SCANn in the firstframe period FRAME1. In such an embodiment, in the second frame periodFRAME2, the data signal DATA may be stably recorded in the pixels PXL(refer to FIG. 5 ), and the pixels PXL may emit light at a desiredluminance.

Since the second pulse width PW2 is not varied and is constantlymaintained while the second period PR2 is relatively reduced, a secondinterval PG2 between the pulses of the scan signals SCAN1 to SCANn inthe second frame period FRAME2 may be less than a first interval PG1between the pulses of the scan signals SCAN1 to SCANn in the first frameperiod FRAME1.

In such an embodiment, since the period (or the refresh rate) of thevertical synchronization signal VSYNC is not changed, the porch periodmay be increased as the display period is reduced. That is, the fourthperiod P4 of the second frame period FRAME2 may be greater than thesecond period P2 of the first frame period FRAME1. In one embodiment,for example, the second period P2 may be about 8 times the first periodPR1 and the fourth period P4 may be about 248 times the second periodPR2.

In an embodiment, as described with reference to FIG. 9 , when themovement speed of the touch input exceeds the reference speed (forexample, when the second movement speed MV_S2 described with referenceto FIG. 8 exceeds the first reference speed MVTH1, the period of thehorizontal synchronization signal HSYNC may be reduced, the displayperiod in the frame period may be reduced, and the porch period in theframe period may be increased. In such an embodiment, as the displayperiod in the frame period is reduced, the data signal may be updated orswitched more quickly during one frame period, and one complete frameimage may be displayed more quickly. Therefore, the screen abnormalityvisually recognized by the user in a screen switching or draggingprocess may be effectively prevented or alleviated.

In such an embodiment, the vertical synchronization signal VSYNC and therefresh rate may be regularly maintained or fixed. Thus, an increase ofpower consumption of the display device 100 may be minimized. In oneembodiment, for example, when the refresh rate is increased by 10%, anincrease rate of the power consumption of the display device 100 may bewithin about 10% to about 15%. When only the display period is decreasedwhile fixing the refresh rate, the increase rate of the powerconsumption of the display device 100 may be about 5% or less.

FIG. 10 is a signal timing diagram illustrating an alternative exemplaryembodiment of the signals in the display device of FIG. 3 . In FIG. 10 ,signals corresponding to the signals shown in FIG. 9 are shown.

Referring to FIGS. 9 and 10 , in a second frame period FRAME2_1, thedisplay device 100 may operate in the second mode. In one embodiment,for example, when the movement speed of the touch input is greater thanthe reference speed, the display device 100 may operate in the secondmode for a specific period.

The period of the vertical synchronization signal VSYNC in the secondframe period FRAME2_1 may be less than the period of the verticalsynchronization signal VSYNC in the first frame period FRAME1.Therefore, a size (or a temporal width) of the second frame periodFRAME2_1 may less than the size (or a temporal width) of the first frameperiod FRAME1, and a refresh rate (or a second frequency FREQ2, forexample, 70 Hz) of a frame image corresponding to the second frameperiod FRAME2_1 may be greater than the refresh rate (or the firstfrequency FREQ1, for example, 60 Hz) of the frame image corresponding tothe first frame period FRAME1.

In such an embodiment, as described above with reference to FIG. 9 , thesecond period PR2 of the horizontal synchronization signal HSYNC in thesecond frame period FRAME2_1 may be less than the first period PR1 ofthe horizontal synchronization signal HSYNC in the first frame periodFRAME1. Therefore, a total time during which the scan signals SCAN1 toSCANn and the data signal DATA are provided in the second frame periodFRAME2_1, that is, the third period P3 (the display period, or theactive period), may be less than the total time during which the scansignals SCAN1 to SCANn and the data signal DATA are provided in thefirst frame period FRAME1, that is, the first period P1. Thus, in thesecond frame period FRAME2_1, the data signal DATA may be updated morequickly, and one complete frame image may be displayed more quickly.

In such an embodiment, a fourth period P4_1 of the second frame periodFRAME2_1 may be equal to or less than the second period P2 of the firstframe period FRAME1. As the fourth period P4_1 is less, the frame rateof the frame images corresponding to the second frame period FRAME2_1may be increased. In such an embodiment, a switching width (or amovement width) between the frame images may be reduced. Therefore, thescreen abnormality visually recognized by the user in the screenswitching process may be effectively prevented or alleviated, and morenatural screen switching may be achieved.

FIG. 11 is a signal timing diagram illustrating another alternativeexemplary embodiment of the signals in the display device of FIG. 3 . InFIG. 11 , signals corresponding to the signals shown in FIG. 9 areshown.

Referring to FIGS. 9 and 11 , in a second frame period FRAME2_2, thedisplay device 100 may operate in the second mode. In one embodiment,for example, when the movement speed of the touch input is greater thanthe reference speed, the display device 100 may operate in the secondmode for a specific period.

The period of the vertical synchronization signal VSYNC in the secondframe period FRAME2_2 (the frame period in the second mode) may be lessthan the period of the vertical synchronization signal VSYNC in thefirst frame period FRAME1. Therefore, a size (or a temporal width) ofthe second frame period FRAME2_2 may less than the size (or temporalwidth) of the first frame period FRAME1, and a refresh rate (or a thirdfrequency FREQ3, for example, 70 Hz) of a frame image corresponding tothe second frame period FRAME2_2 may be greater than the refresh rate(or the first frequency FREQ1, for example, 60 Hz) of the frame image.

A second period PR2_1 of the horizontal synchronization signal HSYNC inthe second frame period FRAME2_2 may be the same as a first period PR1_1of the horizontal synchronization signal HSYNC in the first frame periodFRAME1. Therefore, a total time during which the scan signals SCAN1 toSCANn and the data signal DATA are provided in the second frame periodFRAME2_2, that is, a third period P3_1 (the display period, or theactive period) may be equal to the total time during which the scansignals SCAN1 to SCANn and the data signal DATA are provided in thefirst frame period FRAME1, that is, the first period P1.

In such an embodiment, second pulse widths PW2_1 of each of the scansignals SCAN1 to SCANn in the second frame period FRAME2_2 may be thesame as first pulse widths PW1 of each of the scan signals SCAN1 toSCANn in the first frame period FRAME1. In such an embodiment, a secondinterval PG2_1 between the pulses of the scan signals SCAN1 to SCANn inthe second frame period FRAME2_2 may be the same as the first intervalPG1 between the pulses of the scan signals SCAN1 to SCANn in the firstframe period FRAME1.

In an embodiment, a fourth period P4_2 of the second frame periodFRAME2_2 may be equal to or less than the second period P2 of the firstframe period FRAME1. As the fourth period P4_2 is less, the frame rateof the frame images corresponding to the second frame period FRAME2_1may be increased. In such an embodiment, the switching width (ormovement width) between the frame images may be reduced. Therefore, thescreen abnormality visually recognized by the user in the screenswitching process may be effectively prevented or alleviated, and morenatural screen switching may be achieved.

FIG. 12 is a diagram illustrating an exemplary embodiment of the imagedisplayed on the display device of FIG. 3 . FIG. 12 exemplarilyillustrates the screen abnormality (for example, a screen drag)occurring in a switching process between the frame images when themovement speed of the touch input exceeds the reference speed.

Referring to FIGS. 3, 5, 9, and 12 , as the scan lines SL1 to SLn arearranged along the first direction DR1, the scan signals may besequentially provided to the display portion DISP).

A first image IMAGE1 indicates one frame image without touch input.

A second image IMAGE2 indicates an image at a time point at which anN-th (N is a positive integer) frame image is switched (or updated) toan (N+1)-th frame image according to a scroll input in the seconddirection DR2 (that is, a touch input instructing a screen movement inthe second direction DR2).

As the display device 100 operates in a sequential driving method, theframe images may be sequentially updated along a scan direction (thatis, the first direction DR1). Therefore, the N-th frame image may bedisplayed in a part of a left side of the second image IMAGE2, the(N+1)-th frame image may be displayed in a part of a right side of thesecond image IMAGE2, and a boundary between a held N-th frame image anda refreshed (N+1)-th frame image may be shown discontinuously.

When a length of the second image IMAGE2 in the second direction DR2 isnarrow, since an image (for example, a discontinuous portion between theN-th frame image and the (N+1)-th frame image) provided to the user forthe scroll input in the second direction DR2 is small, the user may notrecognize the screen drag.

However, as described with reference to FIGS. 1 and 5 , since the seconddriver 130 for generating the scan signal is disposed adjacent to theshort side (for example, the first and second short sides SS1 and SS2,(refer to FIG. 1 )), a length of the second image IMAGE2 in the seconddirection DR2 is relatively long, the image (for example, thediscontinuous portion between the N-th frame image and the (N+1)-thframe image) provided to the user for the scroll input in the seconddirection DR2 may be increased, and the screen drag may be visuallyrecognized by the user.

In such embodiment, when the scroll input in the second direction DR2occurs, the display device 100 may update the frame image more quicklyby increasing the porch period and reduce the display period in theframe period. Thus, the screen abnormality visually recognized by theuser in the screen switching process may be effectively prevented oralleviated.

FIG. 13 is a flowchart illustrating a method of driving a display deviceaccording to an embodiment of the disclosure.

Referring to FIGS. 3 and 13 , the method of FIG. 13 may be performed inthe display device 100 of FIG. 3 .

The method of FIG. 13 may including sensing the touch input through thetouch driver 210 (S1310).

When the touch input is sensed, in the method of FIG. 13 , e themovement speed of the touch input may be calculated by the touch driver210 and whether or not the movement speed of the touch input is greaterthan the reference speed is determined (S1320).

As described with reference to FIG. 8 , the method of FIG. 13 mayinclude calculating the movement speed in the second direction DR2 (thatis, the second movement speed MV_S2, refer to FIG. 8 ) perpendicular tothe first direction DR1.

In such an embodiment, the method of FIG. 13 may include increasing theporch period included in the frame period in which one frame image isdisplayed through the processor 300 (S1330) when the movement speed ofthe touch input is greater than the reference speed.

In such an embodiment, as described with reference to FIG. 9 , the porchperiod may be the period between the end time point of the displayperiod and the start time point of the next display period.

The width of the frame period (or the refresh rate of the frame images)may be constantly maintained or fixed. In such an embodiment, since theporch period is increased, the display period may be reduced. That is,the method of FIG. 13 may include reducing the update time of the framedata corresponding to each of the frame images.

Thereafter, the method of FIG. 13 may include displaying the frame imageon the display portion DISP based on the increased porch period (S1340).

In such an embodiment, the method of FIG. 13 may include reducing theporch period included in the frame period in which one frame image isdisplayed through the processor 300 (S1350) when the movement speed ofthe touch input is less than the reference speed.

In one embodiment, for example, the method of FIG. 13 may includereducing the porch period when the porch period is increased as comparedwith the second period P2 as described above with reference to FIG. 9 orequal to the fourth period P4. In one alternative embodiment, forexample, the method of FIG. 13 may include maintaining the width of theporch period as it is when the porch period is the same as the secondperiod P2 described above with reference to FIG. 9 .

In an embodiment, as described with reference to FIG. 9 , the method ofFIG. 13 may include providing the scan signals to the display portionDISP with a shorter period (for example, the second period PR2) throughthe second driver 130, and providing the data signal to the displayportion DISP by switching the data signal with a shorter period throughthe first driver 120.

In such an embodiment, as the display period in the frame period isreduced, the data signal may be updated or switched more quickly duringone frame period, and one complete frame image may be displayed morequickly. Therefore, the screen abnormality visually recognized by theuser in the screen switching process may be effectively prevented oralleviated.

In an embodiment, since the width of the frame period or the refreshrate of the frame images is constantly maintained or fixed, an increaseof the power consumption of the display device may be minimized.

FIG. 14 is a flowchart illustrating a method of driving a display deviceaccording to an alternative embodiment of the disclosure.

Referring to FIGS. 3 and 14 , the method of FIG. 14 may be performed inthe display device 100 of FIG. 3 .

The method of FIG. 14 may include sensing the touch input through thetouch driver 210 (S1410).

In such an embodiment, the method of FIG. 14 may include calculating themovement speed of the touch input through the touch driver 210 when thetouch input is sensed and determining whether or not the movement speedof the touch input is greater than the reference speed (S1420).

In such an embodiment, as described with reference to FIG. 8 , themethod of FIG. 14 may include calculating the movement speed in thesecond direction DR2 (that is, the second movement speed MV_S2, refer toFIG. 8 ) perpendicular to the first direction DR1.

In such an embodiment, the method of FIG. 14 may include increasing therefresh rate of the frame images through the processor 300 (S1430) whenthe movement speed of the touch input is greater than the referencespeed.

In one embodiment, for example, as described with reference to FIG. 10 ,the method of FIG. 14 may include reducing the display period andmaintaining or reducing the width of the porch period. In onealternative embodiment, for example, as described with reference to FIG.11 , the method of FIG. 14 may include maintaining the width of thedisplay period and reducing the width of the porch period.

Thereafter, the method of FIG. 14 may include displaying the frame imageon the display portion DISP based on the increased refresh rate (S1440).

In such an embodiment, the method of FIG. 14 may further includereducing the refresh rate of the frame images through the processor 300(S1450) when the movement speed of the touch input is less than thereference speed.

In one embodiment, for example, the method of FIG. 14 may includeincreasing the refresh rate when the refresh rate is increased ascompared with the first frequency FREQ1 described with reference to FIG.10 or equal to the second frequency FREQ2. In one alternativeembodiment, for example, the method of FIG. 14 may include maintainingthe refresh rate as it is when the refresh rate is equal to the firstfrequency (FREQ1) described with reference to FIG. 10 .

As the refresh rate of the frame images increases, the switching width(or movement width) between the frame images may be reduced. Therefore,the screen abnormality visually recognized by the user in the screenswitching process may be effectively prevented or alleviated, and morenatural screen switching may be achieved.

FIG. 15 is a flowchart illustrating a method of driving a display deviceaccording to further another alternative embodiment of the disclosure.

Referring to FIGS. 3 and 15 , the method of FIG. 15 may be performed inthe display device 100 of FIG. 3 .

The method of FIG. 15 may include obtaining the attitude information ofthe display device 100 through the gyro sensor (or the sensor 400)(S1510).

The method of FIG. 15 may further include determining the screenorientation of the display device 100 based on the attitude information(S1520).

In such an embodiment, as described above, the screen orientation may bea direction in which an image is output based on the display device 100,or a direction from an upper side to a lower side of an image (forexample, a character).

When the screen orientation of the display device 100 is the firstscreen orientation (or the second direction DR2), the display device 100may operate in the first viewing mode (or the vertical direction viewingmode), and when the screen orientation of the display device 100 is thesecond screen orientation (or the first direction DR1), the displaydevice 100 may operate in the second viewing mode (or the horizontaldirection viewing mode).

The method of FIG. 15 may further include determining whether the screenorientation of the display device 100 is the first screen orientation(or the second screen orientation) (S1530), and when the screenorientation is the first screen orientation, the method of FIG. 15 mayinclude increasing the porch period included in the frame period inwhich one frame image is displayed through the processor 300 (S1540).

A configuration for increasing the porch period may be substantially thesame as the configuration for increasing the porch period describedabove with reference to FIGS. 9 and 13 .

In an embodiment, the display device 100 may operate in the verticaldirection viewing mode and a screen (that is, a scroll screen) that isswitched or scrolled in the second direction DR2 may be frequentlydisplayed through the display device 100 when the screen orientation ofthe display device 100 is the first screen orientation. Therefore, whenthe screen orientation is the first screen orientation, the method ofFIG. 15 may effectively prevent or alleviate the screen abnormalityvisually recognized by the user in the screen switching process (thatis, in the process of displaying the scroll screen) by increasing theporch period.

Thereafter, the method of FIG. 15 may include displaying the frame imageon the display portion DISP based on the increased porch period (S1550).

In such an embodiment, the method of FIG. 15 may further includereducing the porch period included in the frame period in which oneframe image is displayed through the processor 300 (S1560) when thescreen orientation of the display device 100 is not the first screenorientation (for example, when the screen orientation of the displaydevice 100 is the second screen orientation).

In one embodiment, for example, the method of FIG. 15 may includereducing the porch period when the porch period is increased as comparedwith the second period P2 described above with reference to FIG. 9 orequal to the fourth period P4. In one alternative embodiment, forexample, the method of FIG. 15 may include maintaining the width of theporch period as it is when the porch period is the same as the secondperiod P2 described with reference to FIG. 9 .

When the screen orientation of the display device 100 is the secondscreen orientation, the display device 100 may operate in the horizontaldirection viewing mode, and a situation in which the scroll screen inthe second direction DR2 is displayed may rarely occur. Therefore, whenthe screen orientation is the second screen orientation, the method ofFIG. 15 may not perform reducing or varying the porch period.

Thus, in such an embodiment, the screen abnormality visually recognizedby the user in the screen switching process may be effectively preventedor alleviated, and the increase of the power consumption of the displaydevice 100 may be minimized.

The invention should not be construed as being limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete and will fully conveythe concept of the invention to those skilled in the art.

While the invention has been particularly shown and described withreference to exemplary embodiments thereof, it will be understood bythose of ordinary skill in the art that various changes in form anddetails may be made therein without departing from the spirit or scopeof the invention as defined by the following claims.

What is claimed is:
 1. A display device comprising: a display panelincluding pixels connected to data lines and scan lines; a displaydriver which provides data signals to the data lines and provides scansignals to the scan lines; and a touch driver which senses a touchinput, wherein, when a movement speed of the touch input is greater thana reference speed, a first period, in which the scan signals and thedata signals are provided is in a frame period in which a frame image isdisplayed, and wherein, when the movement speed of the touch input isgreater than the reference speed, a switching speed of the data signalsis increased in the frame period.
 2. The display device according toclaim 1, wherein each of the scan signals is synchronized with ahorizontal synchronization signal, a period of the horizontalsynchronization signal is reduced, when the movement speed of the touchinput is greater than the reference speed, and the horizontalsynchronization signal defines starts of each of data rows included inframe data corresponding to the frame image.
 3. The display deviceaccording to claim 2, further comprising: a processor which generatesthe horizontal synchronization signal, wherein the touch driver providesa sensing signal to the processor when the movement speed of the touchinput is greater than the reference speed, and the processor reduces theperiod of the horizontal synchronization signal based on the sensingsignal.
 4. The display device according to claim 2, wherein a refreshrate of the frame image is constant.
 5. The display device according toclaim 4, wherein the first period is within a range of about 80% to 90%of a reference time when the movement speed of the touch input isgreater than the reference speed, and the reference time is a period inwhich the scan signals and the data signals are provided when themovement speed of the touch input is less than the reference speed. 6.The display device according to claim 1, wherein the frame periodincludes a second period between the first period thereof and a firstperiod of an adjacent frame period, the adjacent frame period is a frameperiod adjacent to the frame period, and the second period is increasedwhen the movement speed of the touch input is greater than the referencespeed.
 7. The display device according to claim 1, wherein the frameperiod includes a second period between the first period thereof and afirst period of an adjacent frame period, the adjacent frame period is aframe period adjacent to the frame period, and the second period isconstant or reduced.
 8. The display device according to claim 1, whereinthe display panel further comprises light emission control lines, thedisplay driver provides light emission control signals to the lightemission control lines, and the pixels are connected to the lightemission control lines and emit light based on the light emissioncontrol signals.
 9. The display device according to claim 1, wherein thedata lines extend in a first direction and are arranged along a seconddirection intersecting the first direction, the scan lines extend in thesecond direction and are arranged along the first direction, and thedisplay panel is foldable based on a folding axis extending in thesecond direction.
 10. The display device according to claim 9, whereinthe scan signals are sequentially provided to the scan lines along thefirst direction, and the pixels sequentially emit light in response tothe scan signals.
 11. The display device according to claim 10, whereinthe touch driver calculates the movement speed of the touch input, andthe movement speed is a speed of the touch input in the seconddirection.
 12. A display device comprising: a display panel includingdata lines, scan lines, and pixels connected to the data lines and thescan lines, wherein the display panel displays a frame image through thepixels; a display driver which provides data signals to the data linesand provides scan signals to the scan lines; and a touch driver whichsenses a touch input; and a processor which varies a refresh rate of theframe image based on the sensing signal, wherein a frame period, inwhich the frame image is displayed, includes a first period in which thescan signals and the data signals are provided, and a second periodbetween the first period and a first period of an adjacent frame period,the adjacent frame period is a frame period adjacent to the frameperiod, and the processor reduces the first period or the second period.13. The display device according to claim 12, wherein the processorreduces the first period.
 14. The display device according to claim 13,wherein the processor reduces the second period.
 15. The display deviceaccording to claim 12, wherein the processor reduces the second period.16. The display device according to claim 12, wherein the scan signalsare sequentially provided along a first direction, the touch drivergenerates the sensing signal when the movement speed of the touch inputin a second direction is greater than the reference speed, and thesecond direction intersects the first direction.
 17. A method of drivinga display device, the method comprising: sensing a touch input through atouch sensing portion of the display device; increasing a porch periodwhen the movement speed of the touch input is greater than the referencespeed in a processor; and displaying frame images based on the porchperiod on a display panel of the display device, wherein the porchperiod is a period between a time point at which display of a firstframe image among the frame images is ended and a time point at which asecond frame image adjacent to the first frame image is started to bedisplayed, and wherein the increasing the porch period further comprisesreducing an update time of frame data corresponding to each of the frameimages.
 18. The method according to claim 17, wherein a refresh rate ofthe frame images is constant.
 19. A display device comprising: a displaypanel including pixels connected to data lines and scan lines, whereinthe display panel displays frame images through the pixels; a displaydriver which provides data signals to the data lines and provides scansignals to the scan lines; and a processor which varies a porch periodof the frame images in response to movement of a screen corresponding tothe frame images in a direction perpendicular to a scan direction,wherein the porch period is a period between a time point at whichdisplay of a first frame image among the frame images is ended and atime point at which a second frame image adjacent to the first frameimage is started to be displayed.
 20. The display device according toclaim 19, wherein the processor increases the porch period when thescreen moves in the direction perpendicular to the scan direction. 21.The display device according to claim 20, wherein the scan lines arearranged along a first direction, each of the scan lines extends in asecond direction, and the scan direction is in the first direction.